Sarah Thomas Closes in on Record 4-Time Swim Across English Channel 2 Years After Cancer Diagnosis

American Sarah Thomas is on the verge of achieving the seemingly impossible: swimming the English Channel four times, non-stop.

The Denver, Colorado athlete is midway through the fourth leg of her epic swim — a feat that is itself a record — having been in the waters between England and northern France since midnight Saturday. By the time she hits the shores of Kent, England late on Monday, it’s expected that Thomas will have swum non-stop for around 50 hours.

“It’s just incredible,” says swim expert Jonathan Cowie from Outdoor Swimmer magazine. “It’s just an epic, epic swim.” (To track her progress, click here.)

More remarkable still, Thomas, 37, is a cancer survivor, having been diagnosed with an aggressive form of breast cancer in November 2017.

Throughout her treatment — which included chemotherapy, surgery, and radiation — she used the goal of becoming the first person to complete the 84-mile English Channel quadruple as inspiration.

“I’ve been waiting for this swim for over 2 years now and have fought so hard to get here,” Thomas posted on Facebook ahead of her swim. “Am I 100%? No. But I’m the best that I can be right now, with what I’ve been through, with more fire and fight than ever.”

In order to achieve her dream, Thomas will have to navigate the jellyfish, cargo ships and swirling currents of the world’s busiest shipping lane, while battling the sleep deprivation that comes with being awake for more than two days in water temperatures of 64 degrees.

Eating is also incredibly difficult as the strict rules of cross channel swimming prevent her from touching the side of her support boat or any of its crew — even when she reaches dry land.

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Sarah Thomas
Sarah Thomas

“The water isn’t terribly cold but it’s lumpy out there and there’s a bit of wind, so the air isn’t that warm,” team member Elaine Howley — who has been swimming alongside Thomas for support — tells PEOPLE. “Taken altogether it’s a challenging situation.”

Howley continues, “She’s doing marvelously. She had a brief moment of self-doubt at the second turn when she left England the second time to swim to France because it was dark and she thought she was going to land on a beach but she ended up at a sea wall instead.”

“She was a little tired,” Howley adds. “But she had a good solid feed and some warm water, and she got right back into the water by the time the sun came up.”

Thankfully, Thomas has years of marathon swimming experience to fall back on. In March 2019 — just seven months after completing cancer treatment — she swam the Cook Strait between New Zealand’s North and South islands.

Around six months later, on Aug. 10, she also finished a grueling 32-mile, two-way crossing of Colorado’s largest lake, Blue Mesa.

“I’ve never seen a grittier, more resilient personality in my life,” says Howley. “She just guts it out. She decides what she’s going to do, and she follows through. It’s just incredible.”

Despite this, Howley admits that when Thomas landed in France for the second time — a feat only ever achieved by four other swimmers in history — she sighed and said, “Ugh. Now I’ve got to swim back again!”

Midway through the fourth leg of the swim she also told Howley, “I think I’m ready to be done now.”

To help her through these low moments, Thomas is carrying a small pebble from her home lake as “a reminder of home… when it gets hard,” she revealed on Facebook. She also has a large and extremely important community firmly fixed in her mind at all times.

“This swim is dedicated to all the Survivors out there,” she added on Facebook. “This is for those of us who have prayed for our lives, who have wondered with despair about what comes next, and have battled through pain and fear to overcome. This is for those of you just starting your cancer journey and those of you who are thriving with cancer kicked firmly into the past, and for everyone in between. This is for our family and friends who held us in their arms and provided the strength and support we needed in the hardest times. This is for those who struggled alongside us, feeling our pain as if it was their own. I’m holding you all in my heart and swimming for our health and futures. We are stronger together, each and every one of us.”